Question

已知△ABC和△DEF中,AB=2cm,BC=3cm,CA=4cm,DE=7.5cm,EF=10cm,FD=5cm.

Answer 1

证明：

∵AB=2,BC=3,CA=4,DE=7.5,EF=10,FD=5

∴AB/DF＝2/5,AC/DE＝3/7.5＝2/5,BC/EF＝4/10＝2/5

∴AB/DF＝AC/DE＝BC/EF

∴△ABD∽△DFE